RESUMO
The performance of a detection system based on the pulsed fast/thermal neutron analysis technique was assessed using Monte Carlo simulations. The aim was to develop and implement simulation methods, to support and advance the data analysis techniques of the characteristic gamma-ray spectra, potentially leading to elemental characterisation of innocuous objects using the full spectrum analysis (FSA) approach. The simulations were carried out with a simplified tool, based on a 14MeV DT pulse-neutron source and a bismuth-germanate detector. A MCNP-based method for de-coupling the radiation transport in mixed (n,gamma) fields, to generate separate sets of standard detector gamma-ray responses for individual elements, is outlined. When normalised and experimentally benchmarked in terms of the pulse-neutron source production rate, the standard spectra can be incorporated into algorithms for the FSA of in situ measurements and elemental fingerprinting of the inspected object.
